Study of the prevalence of bacteria carrying antimicrobial resistance genes and virulence genes in the intestinal microbiota of healthy individuals

• Grant number: 12/03395-3
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2012
• End date: October 31, 2014
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Antonio Carlos Campos Pignatari
• Grantee: Antonio Carlos Campos Pignatari
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil
• City of the host institution: São Paulo
• Associated researchers: Katya da Silva Patekoski ; Rosa Maria Silva

Abstract

Most of the bacteria involved in infections associated with health care inhabit the intestinal tract, with the Gram-negative bacilli among the most important. Knowledge about resistance and bacterial virulence is generally from studies with clinical isolates, with few studies that focus on the possible reservoirs of these bacteria. The present study aims to assess the prevalence of Gram-negative bacteria resistant to quinolones and ²-lactams antibiotics in stool of healthy individuals, to detect the presence of genes and mutations that confer resistance to these antibiotics in the bacterial samples, to evaluate the sensitivity to other antimicrobials and the genetic similarity between bacterial samples from the same species and similar susceptibility profiles, to check the presence of conjugative plasmids with resistance markers and to evaluate the samples of E. coli as well as the phylogenetic origin and presence of virulence genes. Fecal material will be collected from 137 individuals. The isolation will be performed on petri dishes with MacConkey agar and nalidixic acid (50¼g/mL), with MacConkey agar and discs containing carbapenems (10mg), with MacConkey agar and imipenem (1¼g/mL), with CHROMagarTM ESBL and CHROMagarTM KPC. The susceptibility profile will be evaluated by BD Phoenix system and agar dilution, with characterization of samples with similar profiles by PFGE technique. The presence of conjugative plasmids will be checked by the technique of conjugation. The study of all genes will be performed by PCR, and the mutations verified by sequencing. The knowledge resulting from this study may be important for modeling efforts to control infection and spread of resistance genes, and to contribute to decision making on empirical treatments. (AU)